D

COLD ROTARY FORGING OF SMALL CALIBERGUN BARRELS

DECEMBER 1915

TECHNICAL REPORT

ARSENAL OPERATIONS DIRECTORATE

DISTRIOU110N STATEMENT

Approved lot public toloosel d*isribu*tion unimimlod.

PREPARED BY

ARSENAL OPERATIONS DIRECTORATEROCK ISLAND ARSENAL

ROCK ISAND, ILLINOIS 61201

I

DISPOSITION INSTRUCTIONS:

Destroy this report when it is no longer needed. Do not return tothe originator.

DISCLAIMER:

The findings of this report are not to be construed as an officialDepartment of the Anry position urless so designatea by other authorizeddocuments.

The citation of commercial products in this report does not constitute. .an official indorsement or approvl of such products.

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SECURITY CLASSIFICATION OF THIS PAGE (When, DO& t.nteted)

REPORT DOCUMAENTATION PAGE READ INSTRUCTIONSBEFORE COMPLETING FORM

2.1 GOVT ACESO NO. 3. RECIPIENT'S CATALOG NUMBER

AOD-TR-75ý-,2t1.GV CESO O

CdRoayFring of Small Caliber Gun Barrel s- .7'hnca Riot /.1

(U John/ugenheimer ~ .CN R ATNM

9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT. PROJECT, TASKAREA & WORK UNIT NUMBERS

Arsenal Operations Directorate, SARRI-PRRo:k Island Arsenal AM&GG8K-3-297-O64I3Q

-Rock Island, Illinois 6120111. CONTROLLING OFFICE NAME A140 ADDRESS lie

CDR, Rock Island Arsenal (A Decom 5 eiArsenal Operations Directorate, SARRI-PRRock Island. Illinois 61201 Ii

14. MONITORING AGE NC NAi8A O E S I ft~~ t f o o ~ o U ~ s) 1. SaCURITY CLASS. (of thle .o~

Unclassified

SCHFEO%)LE

16, OiSTRIOUTION STATEMENT (fa Wet Rep~ef)

Approved for public release, distribution unlimited.

]I. DIST RIOUTION STAY IECN T (Wi the .b~troc enIe~d Ito btec 20, ito. t t~dU. mnfReaktt)

IS. SUPPLEMEN.TARY NOTCS

.10 0CO- WORDOS tCdnI0,,i.tU0 ~ 0"f* ij ld It n.lwe*uO ' Shfi Id.,1tt4 by, 610t* nu

1. Rot~ary Forge 4. Chambhering2. Oilot Line 5. Production Process3. Ri flIing 6. Ba rrelIs

10. ARS 0%Ct toweree *I& it ",c*too* a" toewtU~r &V WOC6 fmb..)

7he objective of this program was to provide an improved method of manu-facturing military gun barrels ranging in bore size from .22 to .50 caliber.During this project, suitable equipment was purchased, and a pilot line forcold rotary forging of barrels was established. Excellent bore qualities,reproducibility, reduced process time and reduced tooling costs were demon-strated. By J iling. chambering, and simultaneous exterior co~ntouring, manyconventiofial machining operations were eliminated with a gain in production

DO 1473 LOINT101 0V I *0V SS IS 030S1 ITS

IiN(I ASST Fn .SECURITY CLASSIFICATION OF THIS PAGE(Whant Data Entered)

v 0. CONT.

rate. The cold rotary forging of gun barrels has been implemented as a produc-tion process for the Rock Island Arsenal. Greater utilization will occur whenengineering design is more closely correlated to the manufacturing process.

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PREFACE

This project was accomplished as part of the US Army manufacturingtechnology program. The primary objective of this program is to develop,on a timely basis, manufacturing processes, techniques, and equipmentfor use in production o4- Army materiel.

The cooperation and assistance received from Michael Tanaka, formerproject officer, and from Jack Hogan, forge shop foreman, is gratefullyacknowledged.

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FINAL PROJECT STATUS REPORT (RCS AMCRD-127)US ARMY ARMAMENT COMMAND/ROCK ISLAND ARSENAL

Rock Island, Illinois 61201 DATE: 1 June 1975

1. PROJECT NUMBER. 6737300 BUDGET CODE. PW A3297

2. PROJECT TITLE. MM&T: Cold Rotary Forging of Small Caliber Gun Barrels

3. MAJOR END ITEMS SUPPORTED.

a. MAJOR END ITEMS. Small arms weapon systems.

b. COMPONENTS SUPPORTED.

(1) 7.62mm M219 machine gun barrel(2) 7.62mm M134 mini gun (Gau barrel)(3) .30 caliber machine gun barrel(4) 5.56=m MI6Al rifle barrel(5) 50 cal. M8C spotting rifle barrel(6) 7.62mm Ml4 National Match rifle bw'rel(7) other small arms weapon barrels

K -. 1. FACILITIES SUPPORTED. Rock Island Arsenal (GOGO)Arsenal Operations DirectorateUS Army Aanment CommandRock Island, Illinois 61201

5. TECHNICAL AHEA(S) SUPPORTE*D. Small arms barrel manufacturing technology.

6. MI1STNE ClIAT. None (Project completed)

7. LQvrto,1 OF W011K.

a. In-house and contract.

b. Rock Island Arsenal, pock Inland, Illinois 61201.Glo, Steyr, Auntria

P8 RIOD COV ED. I Dec 74 to 1

9. STATUG OF' 1.INDING (as of 1 JuneI N5

( In-house Contract Totala. Funds Authorized $100 38,0 500 000

b. Ftxndo Obligated 142,123 357,877 500,000(1) 74-F-0313 1,4,641(2) 714-H-2189 1,100(3) 74-M-2479 2,109

.i.. (t.) DAA F,01-3-C-0173 331,561, (5) 7h-C-007 8,460

Project No. 6737300

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In-house Contract Totalc. Funds Expended $142,522 1349,417* $491,939

*All that remains to be expended in the final billing and paymentfor spare parts under Contract NO. 711-C-0077.

d. Percent (%) of PhysicalCompletion 100% 100% 100%

10. PROJECT OFFICER. John Jugenheimer, Ext. 4135

11. ACCOMPLISHMENTS. An evaluation of the configurations of different calibersmall arms rifle barrels was made in conjunction with the rotary forgingprocess. From this, a purchase description was written and submitted forbid for a horizontal barrel forging machine. GFM Machines, Inc. (Steyr,Austria) was awarded the contract for a Model SHK 10 Barrel Forging Machine.The GFM machine has the capabilities of hot or cold forging, rifling, andchambering with simultaneous exterior contouring to precision tolerances.The equipment was installed in the Forge Shop at the Rock Island Arsenal.

The project implemented and tested a pilot line for the cold rotaryforging of several small arms barrels ranging from .17 to .50 caliber. Tool-ing in the form of tungsten carbide mandrels and forging hammers was pro- k

vided by GFM. Darrel preforms were fabricated from GFM design at the RockIsland Arsenal. Conventional chromium-molybdenum-vanadium barrel steel ofhardness Rockwell C25-30 (per Mii-B-1195) was used. Preform design para--. ~meters were programmed into a Hewlett Packard Model 9830A programable cal-

culator. The print-out includes final preform drawings and data that cmabe used directly in machine set-up.

" During the project, .22 caliber M16 (heavy walled configuration), 7.62mW M219 machine gun, 7. 62= M134, .50 caliber M8C upotting rifle, 7.62mm MI4National Match (with double taper exterior contouring) barrela were suecess-fully rifled. Additional rifliwn for .17 caliber (4.32mm) and 5.56= Mannbarrels and rotwy forging of super-&lloy metal U134 barreln for the ResearchDirectorate was aluo done succeausfuly.

•Tuenty-two caliber R16 and 7. 6 2mm barrel3 were successfully rifled andchambered. These two sites of barrels were mowuted on weapon actions andtent fired for accuracy. Both sitze of barrels exceeded military accuracyrequirements. The H.h National Match barrels are currently being adaptedto receivero to be test fired for accuracy under a developaent program bythe W-neral Thomas J.l~dman Laboratory.

a. Tite rotary forging process is an improved method of manufacturingmilitary small arms barrels.

b. Small arms rifle and machine gun barrels from .17 caliber to .50caliber inclusive can be successfully rifled on the GFN Ndoel SIlK 10 Forg-

. tring Machine.

2 Project No. 6737300

c. Rifling and chambering, including simultaneous outside contouring,can be successfully achieved.

d. Rifling is best achieved between a 27% to 29% reduction in cross-sectional area. Rifling with chambering is best achieved between a 37%to 39% reduction.

e. Precision sniper rifle grade barrel rifling occurs in a narrowrange of machine settings. The extremes result in either "underfilling"of the lands (represented as rounded corners)or "overfilling" of the lands

(represented as tearing or gallin jand will drastically reduce mandrel life.

f. Metallurgical analyses demonstrate that rotary forged barrels meetor exceed military requirements. Improved grain structure, increased tough-ness, better corrosion resistance, and finer surface finish result from theprocess. In general, the geometry and surface finish of the mandrel arereflected precisely in the barrel bore. Bore finishes of 8 micro inch(arithmetric average) or iess are possible.

g. Rotary forged barrels exceed military accuracy requirements.

h. Bore variation is drastically reduced and straightness increased.Variations of less than .00015 inches are common.

i. Greater utilizatlon of rotary forging for barrel production willoccur when engineering design is more closely correlated to this process.

12. P 2O AIAI(S). None

13. FUTIRE WORKi. None

a. Any item in the Army Material Plan (AMP) that can be munufacturedmore econmically meid/or with better properties by rotary forging will benio-fit from this project. Military amll arms weaponry will be greatly impro'v-ed by the adoption of thin procen. The benefits to the Covernment inclule:(1) reduced tooling and labor coots and incroaied production by uzing ont,forgtng operation for rifliing, chambering, aid exterior contourin.g, (2)metallurgically improved weoLpons due to finer micro-structure, (3) muchhigher production rates for difficult to machine aiuper-atloy harrel materialsrequired for rapid firing, weapon systems, and (I0) the ability to produceextremely accurate smaul arms independent of operator skills.

b. No by-product discoveries have been encour.tered.

c. The enclosed representative cost reductions have been identified

during thia project (See Inclosure 1)

15. ItIPI...NTATI0PRO, .l,•,U•,.. jUl manufacturing personnel responsible forA bbarrel production have been briefed on the CWI4 machine and the rotary forging

process. A set-up man hat be.n trained In the operation of the machine and"Tset-up procedure. A nelection of four dirferent types of barrels was used

during a two-week tialning session. A M4ethods Engineer worked with the set-up man to develop skills in preparin6 a program method sheet. A Toolitg

3 Project No. 6737300

Engineer was instructed on parameters for tooling, preforms and templatedesign.

During, the training session, a machine set-up and operation guidelinewas prepared and distributed. Method programs of previously forged barrelsof various calibers were included as an aid for future set-ups.

16. REMARKS, The rotary forging process is a revolutionary improvedmethod of rifling and chambering small arms rifle barrels, eliminatingmuch tooling while improving barrel quality. Accuracy data was obtained frombarrels that were not chrome plated, howev-er. Future work would have toinclude the plating process if' an accurate comparison i-s to be madebetween conventionally machined barrels and rotary forged barrels. Ex-tremely precise dimensions for rifling are obtained in a very narrow rangeof machine adjustments, Chambering of barrels after rifling requires agood knowledge of the forging process and considerablc vorking experience.

Future trends in rifle production in private i"dustry all point towardthis new process. A vast majority of commercial shotgun and rifle barrelsmanufectured in our country today are a result of rotary forging. Currently,the production of a .50 caliber barrel is being planned at the RlockIsland Arsenal. This effort includes tPe design and fabrication of thetooling (including mandrels)to support the project. Mandrel production isa .ritical area with only two outside sources being currently available.(Qtrex Div. of Wallace Murz' Corp., U4ewington, Coma; and 0N4, Steyr, Austria.)

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Plant ?.No1ne-ritig Diviaion

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1. Pr! noJect tic. 6"3T300o

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Inclosure 1- Representative Rotary Forge Cost Savings

The fokllowing cost savings are representative of the magnitude of savingsobtainable in producing a rirled and chambered small arms rifle barrel.Additional savings are available in the production of plate-i barrels through

the elimination of the electropolishing operation.

Tooling costs(Rifled & chembered barrel)

Convent ion Rotary Forge(?er 1000 barrels) (Per 5000 barrels)

Body reamer $262.00 Forging mandrels

Second shoulder reamer $250.00 (2@ $450) $900.00

Bullet seat reamer $U00.00 Forging Hammers

Rifling broach $608.00 $2000.O0

D lre reamer (30 $81.00) $ ._ _$243.00

$ 1,563.oo $2900.0G

Tool maintenwa•ce costs h 'Qo.00 0.00

$5,963.00 $k0oo.00

T1 o por bairrel .$ 5.96 $ 0.58

Tool cost uvingz per barral $5.3.

VI 11 'Jeet No. 037300

Operating Costs

(Rifled & Chambered barrel)

Conventional lotary Forge

Drill bariel .0758 Hr Drill Blank .0425 Hr.

HRough Turn barrel .1086 Hr Turn blank .2000 Hr.fr-.

lRough ream barrel .0552 Hr

Finish ream barrel .0552 Ur

Broach rifling .0921 Hr

.3869 Forge rifling &:•: " " .167 Orchamber

Reugh in chamber .1123 Hr

.Smi-fiaihW Ch'ambr .1193 Ur

Finish chamber .!1P UHr

0. 7337 Hr 0.3592 Hr

f 0perating Time zavii4, 0. 3745 Ur Ner Rrrel

Oporting Cout uivi Ws 0 $22.00 pr Hr. $h.24 per barrel

Operating Cost~ auwinga $8.24~ par iUrrtol

Toolita. Cost savinp= $5.14 per Wirrel

STot.a Rotaty Forge Savitid $13. W per 13arrel

Project Ho. 673T300

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DISTRIBUTION

Copies

A. Department of Defense

Defense Documentation CenterATTN: TIPDRCameron StationAlexandria, VA 22314 12

B. Department of the Army

CommanderU. S. Army Materiel CommandATTN: AMCRD-E

AMCRP- IAMCQA-E

5001 Eisenhower AvenueAlexandria, .VA 22333

"CommanderU. S. Army Materiel CoirniandScientific and Technical Information Team - EuropeATTN: AMXST-STL Dr. Richard B. GriffinAPO New York 09710

CommanderU. S. Army Ar~marnnt CocmtandATTN: AMSAR-PPI-K

AMSAR-PPI -WWAAMSAR-RDPA•.SAR-SC"AHSAR-QAE

Rock Isiand,.IL 61201

Oi rectorU. S. Amy Materials and Mechanics Research CenterATTN: AMXNR4MWatertown, MA 02172

DirectorU. S. Aty Maintenance M4anagement CenterATTh: AHXMD-ALexington, KY 40507

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Copies

CommanderU.S. Army Electronics CommandATTN: AMSEL-PP/I/IMFort Monmouth, NJ 07703

CommanderU. S. Army Missile CommandATTN: AMSMI-IIE

AMSMI-PRTRedstone Arsenal, AL 35809

CommanderU. S. Army Tank-Automotive CommandATTN: AMSTA-RK

AMSTA-RCM.1 IWarren, MI 48090

CommanderU. S. Army Aviation Systems CommandATTN: AMSAV-EREP. 0. Box 209St. Louis, MO 63166

CommanderU. S. Army Troop Support CommandATTN: AMSTS-PLC4300 Goodfellow Blvd.St. Louis, MO 63120

CommanderBallistic Missile Pefense SystemsATTN: BNDSC-TS"P. 0. Box 1500Huntsville, AL 35804

Project ManagerMunition Production Base ModPicatinny ArsenalDover, NJ 07801

SComanderVs! Harry Diamond Laboratories

ATTN: AMXDO-RCD'- 2800-Powder Mill Road

:•ilq Adelphi, MD 20783Li4 "

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DISTRIBUTION

CommanderNatick Development CenterATTN: AMXNL-EQKansas StreetNatick, MA 01762 1

"ComnancerU. S. Army Air Mobility R&D LabsATTN: SAVDL-STFort Eustis, VA 23604

CommanderRock Island ArsenalATTN: SARRI-PE 1

SARRI-RS Mr. V. Long 1SARRI-LS 1SARRI-L 1SARRI-LPL 2

CommanderWatervi let ArsenalATTN: SARWV-PPP-WP 1

SARWV-PPI-LAJ 1SARWV-QA 1

Watervliet, NY 12189

CommanderPicatinny ArsenalATTN: SARPA-MT-C 1

SARPA-QA-T-T 1SARPA-C-C 1

Dover, NJ 07801

CommanderEdgewood ArsenalATTN: SAREA-QAAberdeen Proving Ground, MD 21010 1

4 1. imm l # ( ~m ~ .l ~m N I ll, i Ii . ,i +lm i p (i ~ml~m,, ~ m kuNm O m i i

DISTRIBUTION

Copies

DirectorU. S. Army Production Equipment AgencyATTM: AMXPE-MTRock Island ArsenalRock Island, IL 61201 2

DirectorUSAMC Intern Training CenterATTN: AMXMC-ITC-PPERed River Army DepotTexarkara, TX 75501

CommanderU. S. Army Tropic Test CenterATTN: STETC-MO-A (Technical Library)APO New York 09827

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AD Accession No. UNCLASSIFIED

CDR, Rock Island Arsenal I. Rotary ForgeArsenal Operations DirectorateRock Island, Illinois 61201 2. Pilot Line

COLD ROTARY FORGING OF SMALL CALIBER 3. RiflingGUN BARRELS

14. Chambering,

Report AQD-TR-75-001, Dec 75,

(AMS Code 3297.06.7300) Unclassified Report. 5. Production Process

The objective of t)ii~ program was to provide an improvedmethod of miiufacturing military gun barrels rw)glng intbore size from .2e to .O caliber. During 'his project,,uitable equipment was purolased, and a pilot ln.o forcoltd rotary forgir.g of barr-'- war; astablishel. Excellentbore quallties, reproducibility, reduve4 process time andreduced tooling couts were downstrated. By rifling,chambering, and simultaneous exterior contouring, manyconventional machining o, .rations were eliminated with again in productioti rate. The cold rotary forging of gunbarrels hae been implemented as a production process forthe Rock Island Arsenal. Greater 4tilization will occu-when engineering design is mire closely correlated tu the DISTIRIBt~rIONmanufacturing process. Copies available

from DDC.

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